Currently, there is a system which has functions of a radio communication such as cellular communication where a single base station covers a mid to long-distance service area, functions of a WLAN (Local Area Network) with a relatively short-distance service area; and the like. The system provides a communication service through a network formed of multiple different types of networks. There is also a radio communication terminal which is connectable to these networks.
Concerning such a network formed of multiple different types of networks, the 3GPP (Third Generation Partnership Project) discusses radio communication terminals and related communication techniques, the radio communication terminal having functions to communicate with various types of networks such as a cellular network (3GPP network), a WiMAX (Worldwide Interoperability for Microwave Access) type WWAN (Wireless Wide Area Network), a WLAN and the like.
Discussions are made particularly for the purposes such as enabling such different types of networks to achieve seamless mobility and to support multiple application services requiring high QoS (Quality of Service), such as real-time video, VoIP (Voice over Internet Protocol) and important data.
For example, later-mentioned Non-Patent Document 1 discloses a technique for allocating an address when a radio communication terminal moves into and connects to a non-3G network. Use of PMIPv6 (Proxy Mobile IPv6) disclosed in later-mentioned Non-Patent Document 2 is considered for such mobility management in a 3G/non-3G network.
In PMIPv6, a function on the network side supports local mobility. However, there may be situations where the radio communication terminal itself performs mobility management for some reason, such as a case where a network does not support PMIPv6 or where a certain necessity arises in connecting with the correspondent terminal. In this case, the radio communication terminal can perform its own mobility management by using MIPv6 (Mobility Support in IPv6) described in later-mentioned Non-Patent Document 3, for example.
Note that in such a situation, regardless of the number of interfaces in each terminal, multiple addresses may be allocated to a single radio communication terminal due to various factors such as service, connection destination, and state of connection to a roaming network. Moreover, although a radio communication terminal may have multiple location registration nodes in some cases depending on the state of roaming or the like, the radio communication terminal does not recognize the difference among the nodes in most of the cases.
In addition, in a 3GPP network, network access control is performed so as to suit the usage or capability of a radio communication terminal, to cope with load control on the network side, and for other purposes. As a method for such access control, a function of limiting connection to a base station by using SIM (Subscriber Identity Module) information and an access class value which is set for each radio communication terminal, as described in later-mentioned Non-Patent Document 4 is used to allow only specific radio communication terminals, or to enable group-based connectable timing control by forming groups of radio communication terminals satisfying certain conditions (or groups selected at random). Moreover, service-level access control performs management of individual radio communication terminals by using AAA (Authentication, Authorization and Accounting).